The Hi-Wattage model is standard. The wattage's stated are based on heavy current connections with unconfined mounting. The case temperature should not exceed 140 degrees F (60 degrees C). Additionally the Finned Models require 300 cubic feet(8.6 cubicmeters) per minute air flow over their cases. The ambient temperature should not exceed 86 degrees F (30 degrees C). Operation above this temperature the wattage rating should be derated accordingly.